On Nov 20, 8:45=A0pm, Jeff Liebermann <je...@cruzio.com> wrote:> On Sun, 20 Nov 2011 16:47:25 -0800 (PST), "Ron D." wrote:> >I have a cheap Caliper too and it recently went flakey. > > >I did my standard trick: =A0Remove battery. =A0Short battery contacts: > >Insert new battery. =A0Worked. > > My cheap electronic caliper goes nuts when I transmit on UHF anywhere > near it. =A0However, it doesn't require the battery removal ordeal to > recover. =A0I just reset to zero and continue. > > >Mine uses an LR44 and you HAVE TO use an LR44, not a substitute > >battery that you can get a Radio Shack. > >Mechanically they are not the same. > > I beg to differ. =A0The general package name is LR44 in an 11.6mm dia x > 5.4mm thick package alkaline cell. =A0There are slight variations, but > the IEC LR1154 equivalents (LR44/LR154, A76, 157/303/357) are all the > same size. =A0Where you can have problems is that the SR44/SR1154 silver > oxide cells come in the same package. =A0They have about 50% more > capacity and a much flatter discharge curve. =A0Some of the cheapo > calipers crap out below about 1.4V. =A0The alkaline battery has plenty > of capacity left at 1.4V, but the caliper doesn't want to run. =A0If > your caliper cames with a silver-oxide cell, it should probably use > silver oxide batteries. =A0If it came with alkaline and has a short > battery life, it might be worthwhile trying silver-oxide. =A0If you're > ambitious, it might be useful to run the caliper off a bench power > supply and check how low a voltage will work.I just measured a Harbor Freight (Chinese) 8-incher. Drain: 13.5uA (off), 14.5uA (on) Battery low threshold (blinking display): 1.37V Lowest operating voltage: 1.01V So, it's clearly made for silver-oxide cells. The battery low threshold is set appropriately for a silver oxide cell (e.g. SR-44). It's a lousy threshold for using alkalines--they're barely broken in at that voltage. 14.5uA means a year from a silver oxide cell--that's not horrible. -- Cheers, James Arthur
Repaired Harbor Freight digital caliper
Started by ●November 19, 2011
Reply by ●November 20, 20112011-11-20
Reply by ●November 20, 20112011-11-20
On Nov 20, 7:47=A0pm, "Ron D." <ron.doz...@gmail.com> wrote:> I have a cheap Caliper too and it recently went flakey. > > I did my standard trick: =A0Remove battery. =A0Short battery contacts: > Insert new battery. =A0Worked. > > Mine uses an LR44 and you HAVE TO use an LR44, not a substitute > battery that you can get a Radio Shack. > Mechanically they are not the same.You can get the silver oxide cells occasionally from Big Lots, a card of 5 goes for something like $2.50. Other than that, drugstores have 'em for something like $3-5, per cell (!). And yes, they're mechanically the same. -- Cheers, James Arthur
Reply by ●November 20, 20112011-11-20
<dagmargoodboat@yahoo.com> wrote in message news:07d0ac35-1cf3-4ed1-ba85-cd32f2f6ea0b@p2g2000vbj.googlegroups.com...> On Nov 20, 8:45 pm, Jeff Liebermann <je...@cruzio.com> wrote: >> On Sun, 20 Nov 2011 16:47:25 -0800 (PST), "Ron D." wrote: > >> >I have a cheap Caliper too and it recently went flakey. >> >> >I did my standard trick: Remove battery. Short battery contacts: >> >Insert new battery. Worked. >> >> My cheap electronic caliper goes nuts when I transmit on UHF anywhere >> near it. However, it doesn't require the battery removal ordeal to >> recover. I just reset to zero and continue. >> >> >Mine uses an LR44 and you HAVE TO use an LR44, not a substitute >> >battery that you can get a Radio Shack. >> >Mechanically they are not the same. >> >> I beg to differ. The general package name is LR44 in an 11.6mm dia x >> 5.4mm thick package alkaline cell. There are slight variations, but >> the IEC LR1154 equivalents (LR44/LR154, A76, 157/303/357) are all the >> same size. Where you can have problems is that the SR44/SR1154 >> silver >> oxide cells come in the same package. They have about 50% more >> capacity and a much flatter discharge curve. Some of the cheapo >> calipers crap out below about 1.4V. The alkaline battery has plenty >> of capacity left at 1.4V, but the caliper doesn't want to run. If >> your caliper cames with a silver-oxide cell, it should probably use >> silver oxide batteries. If it came with alkaline and has a short >> battery life, it might be worthwhile trying silver-oxide. If you're >> ambitious, it might be useful to run the caliper off a bench power >> supply and check how low a voltage will work. > > I just measured a Harbor Freight (Chinese) 8-incher. > > Drain: 13.5uA (off), 14.5uA (on) > Battery low threshold (blinking display): 1.37V > Lowest operating voltage: 1.01V > > So, it's clearly made for silver-oxide cells. The battery low > threshold is set appropriately for a silver oxide cell (e.g. SR-44). > > It's a lousy threshold for using alkalines--they're barely broken in > at that voltage. > > 14.5uA means a year from a silver oxide cell--that's not horrible. > > -- > Cheers, > James ArthurWhy bother including an on off switch? Cheers
Reply by ●November 20, 20112011-11-20
On 2011-11-20, amdx <amdx@knologynotthis.net> wrote:> On 11/19/2011 9:01 PM, P E Schoen wrote: >> I have two Harbor Freight digital calipers, item #47257, and I've had >> problems with one of them especially, where the display will go blank. >> It seemed to work sometimes if I squeezed the enclosure, and I thought >> it was a bad battery or bad connection. But a fresh battery didn't work. >> > > That's why I like the Dial calipers vs Digital Calipers, no concern > about batteries or electronics.But -- dial calipers are vulnerable to two problems. 1) Drop or bump them and the pinion will disengage from the rack and shift to give a wrong reading. You can work around that by rotating the dial to re-zero it, but past a certain point, it gets to be awkward to read. 2) Small chips can get engaged in the rack and the zero point will shift every time you pass that point. Vernier calipers don't have these problems, but are more difficult to read with aging eyes and poor light. Yes -- there are ways to fix both, but a lot more fiddly than fixing an exhausted battery on the digital calipers. And the digital calipers have two other advantages over dial and Vernier calipers: a) Switch between metric and inch modes at the push of a button, even converting readings already locked in. (Actually, some Vernier calipers have both scales, so this does not apply.) b) Ability to reset the zero where-ever you want, so you can set it to zero on a target dimension, and then read how much you need to machine off in a lathe to see how many passes before you are close enough to do serious measurements. You can even keep a calculator handy to divide by two depending on whether your cross-feed dial reads in diameter or radius. c) (O.K. Three for some people. :-) -- the ability to transfer the measurement to a computer (without typing errors) for statistics or other similar processing.> (Dial Calipers, Item # 66541, Out of Stock) > > Although a couple years ago HF had the 6" Digital calipers on sale for > $9.99, I bought two. They are still in the boxes and I use my Dial > calipers. I think I might give one away as a Christmas present.I have three 6" (150 mm) digital calipers, and a 12" (300 mm) digital caliper. (Not counting two old B&S 6" ones which require mercury cells for power, which are made of unobtanium.) I also have a two dial calipers -- a 6" Phase-II, and a 150 mm Starrett. And two Vernier calipers -- a 6"/150mm and a 24" (I forget whether that one has metric units as well.) However -- the ones which I reach for most of the time are the digital ones -- because of the memory feature and the ability to switch measurement systems to match what I am working on and with. One 6" digital stays near the main lathe (12x24" Clausing) and one near the little CNC lathe in the opposite corner of the shop. The cheapest digital ($18.00 at a hamfest) lives up here by the computer for when I want to measure something quickly. I keep a spare cell (or set as appropriate) in the case of each digital, so I am not out of operation for very long if the cells in the caliper go bad. The dial or the Vernier get used when I expect to be away from batteries for a while -- or in case the production of batteries ceases thanks to some apocalypse. :-) (Or the 24" one for when I need to measure beyond the range of the 12" digital.) Enjoy, DoN. -- Remove oil spill source from e-mail Email: <BPdnicholsBP@d-and-d.com> | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero ---
Reply by ●November 20, 20112011-11-20
On 2011-11-20, N_Cook <diverse@tcp.co.uk> wrote:> amdx <amdx@knologynotthis.net> wrote in message > news:4756b$4ec8f55d$18ec6dd7$12472@KNOLOGY.NET... >> On 11/19/2011 9:01 PM, P E Schoen wrote: >> > I have two Harbor Freight digital calipers, item #47257, and I've had >> > problems with one of them especially, where the display will go blank. >> > It seemed to work sometimes if I squeezed the enclosure, and I thought >> > it was a bad battery or bad connection. But a fresh battery didn't work. >> > >> >> That's why I like the Dial calipers vs Digital Calipers, no concern >> about batteries or electronics. >> (Dial Calipers, Item # 66541, Out of Stock) >> >> Although a couple years ago HF had the 6" Digital calipers on sale for >> $9.99, I bought two. They are still in the boxes and I use my Dial >> calipers. I think I might give one away as a Christmas present. >> Mikek > > > > I've never used the new-fangled ones - do you have to do a clean jaws, close > jaws, zero calibration check/0 reset ,every time you use them ? as the count > must be lost each time it is switched offMost of the newer ones dont really switch off -- just the display is blanked to save power, so the reading is preserved. (But, the battery life is not as good. On the Starrett ones which I have, the battery holder slides in and out, and by sliding it less than 1/16" you can disconnect the battery (thus extending the life) at the cost of having to re-zero when you power them back on. I normally do exactly this. The Mitutoyo is not as convenient to disconnect the batteries, so I live with it -- but it also has an extra feature. Aside from remembering when turned off -- it can remember two zeros -- the absolute zero, and the incremental zero (say you zero it to tell how much left to remove in the lathe), and by pushing a button, you go back to the absolute zero without having to clean the jaws and check. Enjoy, DoN. -- Remove oil spill source from e-mail Email: <BPdnicholsBP@d-and-d.com> | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero ---
Reply by ●November 20, 20112011-11-20
On 2011-11-20, Jamie <jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote:> N_Cook wrote: > >> <stans4@prolynx.com> wrote in message >> news:0156c7a7-8bb2-4f32-922b-89bdd893a682@u6g2000vbg.googlegroups.com...[ ... ]>>>I've never used the new-fangled ones - do you have to do a clean jaws, >> >> close >> >>>jaws, zero calibration check/0 reset ,every time you use them ? as the >> >> count >> >>>must be lost each time it is switched off >> >> >> Used to be, they've improved things. On at least some, the count is >> kept live and just the display is switched off. It all goes away when >> batteries are switched, but that can be lived with. >> >> Stan >> >> +++ >> >> So that explains , down thread, the drawback of dying batteries when >> switched "off" >> >> > I have the HF digital calipers and I need to pull the battery when not > in use other wise, it'll be dead next time I need it. It seems to drain > quite fast.How fast it dies is in part a function of the quality of the batteries used. There are two series, "44" and "357" which are interchangeable (and both magnum handgun calipers, FWIW) which can be either Alkaline cells, or Silver Oxide cells. The Silver Oxide (usually a "SR" prefix to the number) gives *much* better life -- at a significantly higher cost. However, those more expensive ones are the ones which I tend to use. The same in the digital micrometers, which read down to 0.00005" or 0.001 mm.> Other than that, it seems to work very nicely..They are nice to have -- and typically the more expensive ones *do* work better. Enjoy, DoN. -- Remove oil spill source from e-mail Email: <BPdnicholsBP@d-and-d.com> | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero ---
Reply by ●November 20, 20112011-11-20
On 2011-11-20, Bob Engelhardt <bobengelhardt@comcast.net> wrote:> Jamie wrote: >> I have the HF digital calipers and I need to pull the battery when not >> in use other wise, it'll be dead next time I need it. It seems to drain >> quite fast. > ... > > I have one & the battery lasts quite a while (doesn't get used much). > Maybe a different model. Or a different batch. Or different spots on > the quality curve <G>.Or different quality of battery as I just posted above. :-) Enjoy, DoN. -- Remove oil spill source from e-mail Email: <BPdnicholsBP@d-and-d.com> | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero ---
Reply by ●November 20, 20112011-11-20
On Nov 20, 9:55=A0pm, "Martin Riddle" <martin_...@verizon.net> wrote:> <dagmargoodb...@yahoo.com> wrote in message > > news:07d0ac35-1cf3-4ed1-ba85-cd32f2f6ea0b@p2g2000vbj.googlegroups.com... > > > > > On Nov 20, 8:45 pm, Jeff Liebermann <je...@cruzio.com> wrote: > >> On Sun, 20 Nov 2011 16:47:25 -0800 (PST), "Ron D." wrote: > > >> >I have a cheap Caliper too and it recently went flakey. > > >> >I did my standard trick: =A0Remove battery. =A0Short battery contacts=:> >> >Insert new battery. =A0Worked. > > >> My cheap electronic caliper goes nuts when I transmit on UHF anywhere > >> near it. =A0However, it doesn't require the battery removal ordeal to > >> recover. =A0I just reset to zero and continue. > > >> >Mine uses an LR44 and you HAVE TO use an LR44, not a substitute > >> >battery that you can get a Radio Shack. > >> >Mechanically they are not the same. > > >> I beg to differ. =A0The general package name is LR44 in an 11.6mm dia =x> >> 5.4mm thick package alkaline cell. =A0There are slight variations, but > >> the IEC LR1154 equivalents (LR44/LR154, A76, 157/303/357) are all the > >> same size. =A0Where you can have problems is that the SR44/SR1154 > >> silver > >> oxide cells come in the same package. =A0They have about 50% more > >> capacity and a much flatter discharge curve. =A0Some of the cheapo > >> calipers crap out below about 1.4V. =A0The alkaline battery has plenty > >> of capacity left at 1.4V, but the caliper doesn't want to run. =A0If > >> your caliper cames with a silver-oxide cell, it should probably use > >> silver oxide batteries. =A0If it came with alkaline and has a short > >> battery life, it might be worthwhile trying silver-oxide. =A0If you're > >> ambitious, it might be useful to run the caliper off a bench power > >> supply and check how low a voltage will work. > > > I just measured a Harbor Freight (Chinese) 8-incher. > > > Drain: 13.5uA (off), 14.5uA (on) > > Battery low threshold (blinking display): 1.37V > > Lowest operating voltage: 1.01V > > > So, it's clearly made for silver-oxide cells. =A0The battery low > > threshold is set appropriately for a silver oxide cell (e.g. SR-44). > > > It's a lousy threshold for using alkalines--they're barely broken in > > at that voltage. > > > 14.5uA means a year from a silver oxide cell--that's not horrible. > > > Why bother including an on off switch?It's really not worth it for 1uA. If I designed these, I'd shoot for 2uA active draw, like the Mitutoyos, and set the battery low threshold at 1.1V (for alkalines). The battery consumption is the biggest fault with these. Apart from that, they're impressive. I sometimes think about wiring up a "AAA" or solar cell and just forgetting it, but for $0.50 a year it's not worth the trouble. -- Cheers, James Arthur
Reply by ●November 20, 20112011-11-20
On 2011-11-20, N_Cook <diverse@tcp.co.uk> wrote:> Dave Plumpe <lastname@mindspring.com> wrote in message > news:dcCdnbxH1tldnVTTnZ2dnUVZ_qednZ2d@earthlink.com... >> Not only do they remember where Zero is, they even keep track of any >> movement that occurs while they're turned off. Smart little devils. >> >> I find myself more & more reaching for the digital ones for the ease of >> swapping between inches & millimeters.[ ... ]>> "N_Cook" <diverse@tcp.co.uk> wrote in message >> news:jaatmo$4n4$1@dont-email.me... >> > >> > I've never used the new-fangled ones - do you have to do a clean jaws, >> > close >> > jaws, zero calibration check/0 reset ,every time you use them ? as the >> > count >> > must be lost each time it is switched off >> > >> >> > > An engineer told me never close the jaws of a micrometer or vernier calipers > for storage, leave the jaws open slightly.A micrometer should never be stored closed. (Thermal changes in dimensions can stress the components and reduce accuracy. Vernier calipers should not have a problem as long as you don't *lock* them closed -- either with the slide or the fine adjust slide.> Do these digitally things require > the jaws closing before switching off ? How do they know of any movement of > the jaws when switched off elsewise?Most modern digital calipers only shut off the display, and keep the counters and sensors powered up, so they can know where they are when the display is switched back on -- and some will even switch the display back on when it senses motion above some minimum value. Enjoy, DoN. -- Remove oil spill source from e-mail Email: <BPdnicholsBP@d-and-d.com> | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero ---
Reply by ●November 20, 20112011-11-20
On 2011-11-20, Jeff Liebermann <jeffl@cruzio.com> wrote:> On Sun, 20 Nov 2011 13:38:36 -0000, "N_Cook" <diverse@tcp.co.uk> > wrote: >>An engineer told me never close the jaws of a micrometer or vernier calipers >>for storage, leave the jaws open slightly. > > True. With gear type calipers, the lubricating grease tends to > migrate to that position. If a sufficiently filthy environment, an > lump of dirt encrusted grease will be left in that position. If it > happens to be at 0.0, then it will be difficult to accurately > calibrate the mechanism.But he said "Vernier calipers" which have no such mechanism. Though people tend to lock the slides, so thermal stress distortion could be a problem with them stored closed and locked.> There are also some minor reasons, such as > the tendency for two parallel surfaces to trap moisture between them > and rust.Assuming non stainless steel jaws. (I've never seen calipers with carbide faced jaws, unlike good micrometers.) [ ... ]>>How do they know of any movement of >>the jaws when switched off elsewise? > > Only the display is turned off. The pulse counting mechanism is still > operating and functional. The downside is that the battery will be > dead in about 6-9 months. Most include a spare LR44 battery. I had > to buy a pile of them to keep my calipers going. Somehow, the battery > is usually dead when I need to use them. > > 50 batteries for $3.75 ><http://www.ebay.com/itm/220751739681>There is your problem -- cheap cells. Don't use the LR44 (those are alkaline batteries), use the SR44 and SR357 (Silver Oxide cells, with much longer life). Then things will probably last at least six months in storage. The SR44 and SR357 are pretty much interchangeable. I don't even know why there are the two series -- though you will often find them with both designators marked on the same cell or packaging. :-)> I have an expensive set of Starett calipers (both metric and US). I > use them more often than the electronic variety, mostly out of habit. > My most useful measuring tools are my 6" pocket steel scale and a tape > measure.While I tend to use the digital calipers by preference. Half as many calipers needed to cover the metric and inch measurements. Enjoy, DoN. -- Remove oil spill source from e-mail Email: <BPdnicholsBP@d-and-d.com> | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero ---
